1. Field of the Invention
The present invention is related to a mode converter for microwave, and more particularly to an isolated dual-mode converter and applications thereof.
2. Description of the Prior Art
A mode converter converts a microwave in a mode to a microwave in another mode. For example, for an application in microwave heating, such as plasma heating or material processing, the mode converter can convert an asymmetrical mode into a symmetrical mode, so as to provide more uniform microwave heating. For an application in a rotary joint of a radar system or satellite system, the mode converter converts a commonly used transmission mode into a mode which is not affected by rotation or vice versa. Such mode converter should transmit the mode unaffected by rotation with almost no loss.
Prior art mode converters for microwave heating are single-mode converters. In such way, even the converted mode is of circular symmetry, the uniformity of the electric field intensity of a single mode is still limited. Generally speaking, a rotary joint may include single-mode converters for single-channel transmission, or dual-mode converters for dual-channel transmission. However, prior art mode converters for rotary joint typically include a complicated converting structure, such as the Marie transducer.
Therefore, a dual-mode converter that provides more uniform electric field intensity distribution and has a simpler structure is highly desirable.